Land Mammals of the Everglades

Most native mammals are of widespread distribution in North America. Common examples include the Virginia opossum, gray squirrel, common raccoon, northern river otter, gray fox, and whitetailed deer. Other examples of widespread species that are present but now uncommon in South Florida are the short-tailed shrew, black bear, eastern fox squirrel, mink, and panther. Other common mammals are species widespread in the southeast coastal plain, such as the marsh rabbit, cotton mouse, hispid cotton rat, and marsh rice rat. A regional pattern observed in several mammals is the occurrence of subspecies in the Florida Keys that have probably evolved very recently, after isolation by rising sea level. Examples are the Key Largo cotton mouse, Key Largo woodrat, lower keys marsh rabbit, and key deer.

Four members of the weasel family occur in South Florida: two skunks, the northern river otter, and the southern mink. Both skunks are seldom seen (or smelled). The spotted skunk is the rarer of the two, and neither inhabits wetlands. Northern river otters, which are more at home in water than on land, are reasonably common but usually seen only in the dry season, when they use roadside canals, particularly along the Shark Valley Road (Figure 19.1). The South Florida population of the mink, sometimes called the Everglades mink, is separated by more than 100 miles from other Florida populations. Individuals are rarely encountered, and most of what is known about them — distribution, body measurements, diet, and so on—is from examination of occasional roadkills along the Tamiami Trail in the Everglades and Big Cypress Swamp. Like the otter, the mink is semiaquatic.

Raccoons and marsh rabbits were formally the most commonly seen mammals in the Everglades, but both have apparently declined greatly in numbers, almost certainly the result of python predation.

By far the rarest large mammal in South Florida is the panther. A panther’s home range is typically about 250 square miles for males and less than 100 square miles for females. Travel is normally during the night, but in cooler winter weather they may move also during daylight. Panthers are mostly solitary, except for the 12–18 months when a female is raising her one to four kittens. Deer and feral hogs are the Florida panther’s preferred prey.

In the early 1970’s, the entire population was estimated at 12-20 individuals, primarily confined to the Big Cypress Swamp and northward just across the Caloosahatchee. It is estimated that a population of at least 240 individuals is required to be demographically stable and large enough to effectively maintain genetic integrity.

In addition to the Florida panther, there are three moderately sized terrestrial carnivores in South Florida: the bobcat, and two canines, the gray fox and the recently re-naturalized coyote.

There are several introduced mammals in South Florida. Two are common enough to be of ecological significance: the black rat and the domestic pig.

Most native mammals are of widespread distribution in North America. Common examples include the Virginia opossum, gray squirrel, common raccoon, northern river otter, gray fox, and whitetailed deer. Other examples of widespread species that are present but now uncommon in South Florida are the short-tailed shrew, black bear, eastern fox squirrel, mink, and panther. Other common mammals are species widespread in the southeast coastal plain, such as the marsh rabbit, cotton mouse, hispid cotton rat, and marsh rice rat. A regional pattern observed in several mammals is the occurrence of subspecies in the Florida Keys that have probably evolved very recently, after isolation by rising sea level. Examples are the Key Largo cotton mouse, Key Largo woodrat, lower keys marsh rabbit, and key deer.

Marine Mammals

Two marine mammals of note in southern Florida are the Atlantic bottlenose dolphin and the endangered Florida manatee. Bottlenose dolphins are often seen in the marine coastal waters of South Florida, including shallow bays, where they feed on fish. The Florida manatee, by contrast, is a rather sluggish vegetarian and is one of the few tropical marine mammals. An important part of maintaining the species is protecting good seagrass habitat for their foraging.

Lodge, Thomas E.. The Everglades Handbook. CRC Press. Kindle Edition.